1. Solar Technologies and Systems

2. Resource availability

3. Solar Energy in the World

4. Solar Energy in Pakistan

6. Pyranometer (Total Radiation)
Pyrheliometer (Beam/direct Radiation)

7. Radiometer (Short & long wave Radiation)
Tracking System

8. Solar Thermal Systems Low Temperature Systems
Solar water Heating Systems
Solar Space Heating
Solar Air Conditioning
Solar Pool heating
Solar Cooking
Solar Ventilation
Power Generation
High Temperature Systems
Solar Power Towers
Solar Dish-Engines
Solar Hydrogen Production

9. Low Temperature Solar Thermal Energy Conversion Applications
Low temperature solar thermal systems collect solar radiation to heat air and water for many applications including:
Water heating.
Domestic Hot Water.
Industrial and Process hot water.
Swimming Pool Heating.

10. Low Temperature Solar Thermal Energy Conversion Applications
Space heating, ventilation and cooling.
Solar cooking.
Water desalination.
Crop drying.
Power generation.

11. 1. Solar cells and modules
5. Solar building design
4. Solar thermal systems
2. Electrical systems
3. Storage systems

12. Water heating
Solar water heater systems are a well-tried and tested technology.
They are suitable for both new-build and retrofit.
Solar water heater able to provide 70-80% of domestic hot water needs over the year.
There are many possible designs for a solar water heater.

13. Components of Solar Water Heaters
In general, it consists of three main components:
Solar collector, which converts solar radiation into useable heat.
Storage tank to store the solar heated water.
Heat exchanger, pump, controller module, which transfers the heat from the solar collector into the potable water.

14. Solar Collectors There are three types of solar collectors:
Flat plate solar collector.
Unglazed flat plate solar collector.
Glazed flat plate solar collector.
Evacuated tube solar collector.
Parabolic Troughs Collectors

15. Types of water circulating
Water circulating might be passive and active systems.
Passive systems rely on gravity and the tendency for water to naturally circulate as it is heated, allowing water or heat-transfer fluid to move through the system without pumps.
Because they contain no electric components, passive systems are generally more reliable, easier to maintain, and possibly longer-lasting than active systems.

16. Advantages of passive solar water heaters:
Passive circuits don’t rely on electrically powered pumps to circulate the heat-transfer fluid and they are relatively cheap.
Disadvantages of passive solar water heaters :
They require careful planning to optimize performance and there is a poor control of over-heating.

17. Active circulation ‘Pumped circulation’
The pump circulates the heat-transfer fluid from the collector panels through the heat exchanger in the hot water cylinder and back to the solar collectors for re-heating.

18. Advantages of active circulation:
Integral protection against freezing
Overheat control
Heat is delivered from the collector at optimal rate
Greater choice of collector and pipe layout
Reduces heat loss through pipes

19. Disadvantages of active circulation:
Increased complexity
Pump requires electricity (though this can be alleviated by PV supply)
More expensive

20. Active solar heating circuits
Primary circuits transfer may be Direct (Open) or, the more usual Indirect (closed):
Direct (Open) circuits
Direct circuits are those that directly heat the water that flows from the household taps. They are rarely used.
Advantages of direct circuits :
Simplicity and increased efficiency over indirect circuits. through reduction of heat transfer loss.

21. Disadvantages of direct circuits :
They are subject to freezing unless the water is drained-back when the pump switches off, which puts constraints on the positioning of the collectors in relation to the feed tank.
As new water continually flows through the collectors, possibility of foul building in the collector waterways resulting in loss of efficiency.
Pump requires electricity (though this can be alleviated by PV supply)
More expensive

22. Indirect (closed) circuits
Most circulation systems are indirect. Indirect circuits use a separate ‘heat-transfer fluid’ circuit to transfer heat from the collectors to the pre-heat cylinder.
Their main advantage is that they can employ a wide range of materials and fluids as part of the circulation.

23. Space heating, ventilation and cooling.
Active space heating.
Water space heating
Air space heating
Passive space heating and cooling.
Passive space ventilation.
Space air conditioning.
Solar cooking.
Water desalination.
Crop drying.

24. Thank you

25. Passive Solar Space Heating
passive solar heating allows the sun to do all the work.
That is, there is no additional mechanical assistance.
In cold climates, south-facing windows designed to let the sun's heat in while insulating against the cold are ideal.
In hot and moderate climates, the strategy is to admit light while rejecting heat.

26. Passive Solar Space Heating
Passive solar heating system may be direct or indirect gain.
Direct solar gain system
The sun's heat is stored by the building's inherent thermal mass in materials such as concrete, stone floor slabs, or masonry partitions that hold and slowly release heat.

27. Passive Solar Space Heating
Direct solar gain system
In this direct gain design - A direct gain design with an interior water wall for heat storage.  Heat stored in the water wall is radiated into the living space at night.
Diffusing glazing materials. Translucent glazing scatters sunlight to all storage surfaces

28. Passive Solar Space Heating
Indirect Solar Gain System
Indirect gain water wall collects and stores heat during the day. Heat stored in indirect gain water wall is radiated into the living space at night.
Indirect gain Trombe wall stores heat during the day. Excess heat is vented to the interior space. At night Trombe wall vents are closed and the storage wall radiates heat into the interior space.

29. Passive Solar Space Heating
Indirect isolated Solar Gain System
Attached greenhouse with vented storage wall. Heat is stored in the wall during the day - excess heat is vented to the interior space. At night the wall vents are closed and stored heat is radiated to both the greenhouse and the interior space.

30. INDIRECT GAIN: THERMAL STORAGE WALL
COLLECTORS
SAME SURFACE AREA AS STORAGE
SEPARATED BY 2”-6”
ABSORBER
DARK COLOR
SELECTIVE SURFACE
STORAGE
SIZE DEPENDENT ON LAT. & AVG. TEMP.
8”-12” THICKNESS
DISTRIBUTION
UPPER AND LOWER VENTS
2 SQ. FT. FOR EVERY 100 SQ. FT. MASS

31. Passive Solar Space Heating
Indirect isolated Solar Gain System
Heating cycle - Roof pond collects and stores heat during the day. At night roof ponds are covered and stored heat is radiated into the space below.

32. Passive Solar Space Cooling
An overhang above a south window will shade the window completely from early May to mid-August, yet allow for winter sun access. Shading devices should be sized using the given graphic method.

33. Passive Solar Space Cooling
Roof bonds utilizing cool, clear night-skies can provide total cooling. Panels are kept closed during the day and opened after Dusk to radiate out the absorbed day time interior heat.

34. Passive Solar Space Cooling
Open pond with water wall - combined systems can be devised to provide direct cooling for all interior spaces.

35. Passive Solar Ventilation
An indirect gain mass wall can be used to significantly increase ventilation rates in adjoining spaces.

36. Passive Solar Ventilation
Thermal chimneys can be constructed in a narrow configuration (like a chimney) with an easily heated black metal absorber on the inside behind a glazed front that can reach high temperatures and be insulated from the house.

37. Unglazed Flat Plate Solar Collectors
Low cost
Low temperature
Lightweight
Seasonal pool heating

38. Glazed Flat Plate Solar Collectors
Moderate cost
Higher temperature operation
Can operate at mains water pressure
Heavier

39. Cross Section of Flat Plate Solar Collector

40. Absorber Plate
Is made of copper fins welded to copper risers by plasma welder.
Absorber is coated by selective black crystal coating with absorptivity α =0.96 and emissivity Є=0.08

41. Efficiency Flat Plate Solar Collector

42. Evacuated Tube Collectors
Higher cost
No convection losses
High temperature
Cold climates
Installation can be more complicated

43. Evacuated Tube Collectors
Very little heat loss
Good solar capture at various angles
Very little fluid outdoors
Can replace components
Comes in different sizes

44. Evacuated Tube Collectors

45. Efficiency comparison

46. Passive solar water heating system
Easy to install and maintain; no moving parts
Storage tank must be installed above the collector
Uses no electricity;

47. Passive solar water heating system

48. Passive solar water heating system

49. Active indirect solar heating system

50. Active closed solar heating system

51. Active closed solar heating system

52. Active open solar heating system

53. System Configuration

54. Active solar heating system
The main components on an active solar water heating system are
Solar collector
A circulating system
Storage tank
Back up heating system
Control system

55. Solar Heating Systems
Direct heating of fluid; no conversion to electricity
Components
solar thermal collectors
fluid system to move heat (not electricity)
reservoir to stock heat for later use
Common uses
Heat water for home or pool

56. Active water space heating system
The system components in an active space heating application are the same for water heating
with the addition of radiators for space heating or under floor heating coils or even forced air systems.

57. Active air space heating system
A transpired air collector preheats air for building ventilation by using a fan to draw fresh air through the system. Outside (ambient) air passes through holes in the collector (absorber) and is heated as it is drawn up the air space (plenum) between the collector and the south wall of the building.

58. Solar Cooking
Solar cooking and baking are easy passive solar energy application. Solar cookers are safe around children and provide a great way to learn about and use solar energy. Solar cookers are clean, convenient, non-polluting and easy on the environment.

59. Solar Cooking

60. Solar Cooking

61. Solar Cooking

62. Solar Cooking

63. Solar Assisted Air Conditioning

64. Solar Assisted Air Conditioning
                                                                                                                                                      

65. Solar Assisted Air Conditioning

66. Solar Water Desalination
Solar  still is a device to desalinate impure water like  brackish  or saline water. It a simple device to get potable/fresh distilled water  from  impure  water, using solar energy as  fuel, for  its various applications in domestic, industrial and academic sectors.
Advanges:
Produces pure  water  
No prime movers required
No conventional energy required
No skilled operator required
Local manufacturing/repairing
Low investment
Can purify highly saline water (even sea water)

67. Solar Still / Desalination

69. Solar Water Desalination

70. Solar Food/Crop dryer
Solar heat is often the preferable choice for crop drying because this type of heating doesn't burn or harm delicate foods, which often occurs when using steam or burning fuels.
Advantages for using solar heating for crop drying include:
Solar energy is free, thus no air heating costs once the system is installed
This system creates no pollution
The solar wall is an all metal construction, ensuring a long system life
The fan system is the only moving part, making this system virtually maintenance free
Low cost and easy installation
Works as a heat exchanger at night to heat air

72. Solar Crop dryer

73. Solar Power Generation

74. Solar Power Generation
Prototype tower
Spain

75. The Idea of downdraft tower
Solar Power Generation
The Idea of downdraft tower

76. The Idea of Solar Driven ORC
Solar Power Generation
The Idea of Solar Driven ORC

77. Parabolic Collectors
A parabolic mirror concentrates the sun on a dark painted pipe placed in the focus of the parabola. The insulation may provided by a front glass that protects the reflecting surface and by a circular tube around the pipe, that allows vacuum insulation between them. The temperature upper limit is imposed by piping materials.

78. Trough Systems
High-temperature system is the trough system, in which the troughs focus sunlight onto steel pipes or glass tubes. The heat transfer fluid in the pipes reaches more than 700 degrees F and flows through a heat exchanger, providing superheated steam for a turbine generator.

79. Parabolic Collectors

80. Parabolic Trough Collectors

82. Different types of collectors